Pressure testing and refrigerant recharging hose assembly for automobiles

ABSTRACT

A combination pressure measurement/refrigerant charging apparatus may include a shutoff valve that includes a piercing pin and a pressure gauge. The piercing pin may be used to pierce a refrigerant can. The pressure gauge may be used as a handle for operating the shutoff valve. A first end of a hose may be coupled to the shutoff. A quick coupling device may be coupled to a second end of the hose. The quick coupling device may be used to couple the apparatus to a refrigerant system.

BACKGROUND

1. Field of the Invention

The present invention generally relates to refrigerant chargingapparatus. Certain embodiments relate to refrigerant charging andpressure testing assemblies useable to charge a refrigerant system(e.g., a motor vehicle refrigerant system).

2. Description of Related Art

One common technique for assessing the refrigerant charge of arefrigerant system (e.g., an automotive vehicle air conditioning system)is to check the pressure within the refrigerant system by coupling anend of a pressure gauge hose assembly to a service fitting portion ofthe refrigerant system (e.g., a low-pressure side fitting of therefrigerant system). The pressure gauge may be read, and the pressuregauge hose assembly may be removed from the refrigerant system. If thepressure gauge reading indicates that the refrigerant charge is below adesired level, a charging hose assembly may then be coupled to therefrigerant system, and refrigerant may be added to the refrigerantsystem through the charging hose assembly.

A first end of a charging hose assembly typically includes a coupling,which may be releasably coupled to the service fitting. A second end ofthe charging hose assembly typically includes a shutoff valve that maybe secured to an outlet of a pressurized refrigerant container (e.g., arefrigerant can). During use, the charging hose assembly is coupled tothe service fitting of the refrigerant system and the valve is opened toallow refrigerant to flow into the refrigerant system from thepressurized refrigerant container. After allowing some refrigerant toflow into the refrigerant system, the charging hose assembly may beremoved from the service fitting. The pressure gauge hose assembly isagain coupled to the service fitting to assess a refrigerant charge ofthe refrigerant system. After the refrigerant charge is assessed, thepressure gauge hose assembly may be removed from the refrigerant system.

If the refrigerant charge is below a desired level, the charging hoseassembly may be reattached to the service fitting and more refrigerantmay be added to the refrigerant system. The refrigerant charge may thenbe reassessed with the pressure gauge hose assembly. These steps may berepeated, using the separate hose assemblies, until the measuredpressure within the refrigerant system indicates that the refrigerantsystem is adequately charged with refrigerant.

U.S. Pat. No. 6,609,385 to Ferris et al. and U.S. Patent ApplicationPublication No. 20040079092 to Ferris et al., each of which isincorporated by reference as if fully set forth herein, disclose arefrigerant charging/pressure testing hose assembly that is useable toboth check the pressure in a refrigerant system and, if necessary, addrefrigerant to the refrigerant system. The assembly includes arefrigerant hose with a quick disconnect coupler at one end that isconnectable to a service fitting of a refrigerant system, apiercing-type shutoff valve at the other end that is connectable to arefrigerant container, a pressure gauge coupled into an intermediateportion of the hose, and a check valve in the hose between the shutoffvalve and the pressure gauge.

Some manifold assemblies may also be used to pressure test and/or chargea refrigerant system. For example, QUEST™ brand part# 413 (availablefrom EF Products, Inc., Dallas, Tex.) is an R-134a Manifold Gauge foruse by professional service personnel. Part# 413 includes two pressuregauges. One pressure gauge may be coupled to the low-pressure side of arefrigerant system using a hose. The other pressure gauge may be coupledto the high-pressure side of the refrigerant system using a hose. Bothof the gauges are coupled to handle-operated valves that open and closeflow to the pressure gauges from the hoses. In the manifold, bothpressure gauges and both hoses (i.e., the low-pressure side of therefrigerant system and the high-pressure side of the refrigerant system)are in fluid communication with a third hose that may be coupled to arefrigerant container (either a 30 lb. cylinder of refrigerant or, withan adapter, a refrigerant can). Thus, the refrigerant system may becharged through the low-pressure side or the high-pressure side of therefrigerant system. Charging of a refrigerant system through thehigh-pressure side of the refrigerant system may be dangerous and shouldonly be performed by professional service personnel.

SUMMARY

In an embodiment, a combination pressure measurement/refrigerantcharging apparatus may include a shutoff valve. The shutoff valve mayinclude a piercing pin and a pressure gauge. The piercing pin may beused to pierce a refrigerant can during use. The pressure gauge may beused as a handle for operating the shutoff valve during use. A first endof a hose may be coupled to the shutoff valve. A quick coupling devicemay be coupled to a second end of the hose. The quick coupling devicemay be used to couple the apparatus to a refrigerant system. In someembodiments, the quick coupling device may only couple to a low-pressureside of the refrigerant system.

A pressure of the refrigerant system may be measured when the shutoffvalve is closed. Fluid, either a liquid or a gas, may be allowed to flowfrom the refrigerant can to the refrigerant system when the shutoffvalve is open. The piercing pin may be moved back and forth relative toa sealing seat by operating (e.g., rotating) the pressure gauge. Thismovement of the piercing pin may open and close the shutoff valve.

In an embodiment, a combination pressure measurement/refrigerantcharging system may include a conduit. The conduit may be coupled to arefrigerant can and to a low-pressure side of a refrigerant system. Thepressure measurement/refrigerant recharging system may include a valve.The valve may control a flow of fluid through the conduit. Thus, thevalve may control the flow of fluid between the refrigerant can and thelow-pressure side of the refrigerant system.

In certain embodiments, a first pressure gauge may be in fluidcommunication with the conduit. The first pressure gauge may be coupledto the low-pressure side of the refrigerant system. The first pressuregauge may operate the valve to control fluid flow through the conduit. Asecond pressure gauge may be coupled to a high-pressure side of therefrigerant system. The second pressure gauge may be isolated fromfluids that flow through the conduit.

In certain embodiments, the conduit and the valve may be located insidea body (e.g., a manifold). The first pressure gauge and the secondpressure gauge may be coupled to the body. A hose may couple the conduitto a refrigerant can. A can piercing valve may be coupled to an end ofthe hose that is coupled to a refrigerant can. A second hose may couplethe first pressure gauge to the low-pressure side of the refrigerantsystem. A third hose may couple the second pressure gauge to thehigh-pressure side of the refrigerant system. The second and third hosesmay include shutoff valves and/or quick coupling devices. The quickcoupling devices may be used for coupling to the refrigerant system.

In an embodiment, the first pressure gauge may be used as a handle tooperate (e.g., open and close) the valve. Closing the valve may allow apressure of the low-pressure side of the refrigerant system to bemeasured. Opening the valve may allow fluid to flow from the refrigerantcan to the refrigerant system.

The valve may include a pin and a sealing seat. The valve may be closedwhen a portion of the pin presses against the sealing seat. Operation(e.g., rotation) of the first pressure gauge may move the pin back andforth relative to the sealing seat. Thus, operation of the firstpressure gauge may open and close the valve by moving the pin relativeto the sealing seat.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present invention may become apparent to those skilledin the art with the benefit of the following detailed description andupon reference to the accompanying drawings in which:

FIG. 1 depicts an embodiment of a pressure gauge and valve assembly.

FIG. 2 depicts an embodiment of a pressure gauge, valve, and hoseapparatus.

FIG. 3 depicts a flowchart of an embodiment of a method for pressuretesting and/or recharging a refrigerant system.

FIG. 4 depicts an embodiment of a pressure measurement and chargingassembly.

FIG. 5 depicts an embodiment of a pressure measurement and chargingassembly with hoses.

FIG. 6 depicts a schematic representation of a pressure measurement andcharging assembly as depicted from a front-end view of the assembly.

FIGS. 7A-7D depict cross-sectional representations of a low-pressureside of a pressure measurement and charging assembly.

FIGS. 8A-8C depict cross-sectional representations of a low-pressureside of a pressure measurement and charging assembly.

FIGS. 9A-9C depict cross-sectional representations of an embodiment ofan outer body front portion.

FIGS. 10A-10C depict cross-sectional representations of an embodiment ofan outer body rear portion.

FIGS. 11A-11D depict an embodiment of a plunger.

FIGS. 12A and 12B depict cross-sectional representations of anembodiment of a pin.

FIG. 13A depicts an embodiment of a plunger in an opening in an openfluid flow position.

FIG. 13B depicts an embodiment of a plunger in an opening in a closedfluid flow position.

FIG. 14 depicts a flowchart of an embodiment of a method for pressuretesting and/or recharging a refrigerant system.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and may herein be described in detail. Thedrawings may not be to scale. It should be understood, however, that thedrawings and detailed description thereto are not intended to limit theinvention to the particular form disclosed, but on the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the present invention as definedby the appended claims.

DETAILED DESCRIPTION

FIG. 1 depicts a cross-sectional representation of an embodiment of apressure gauge and valve assembly. Assembly 100 may include body 102 andgauge 104. Gauge 104 may be a pressure gauge or other pressuremeasurement device. Gauge 104 may be used as a handle to operateassembly 100. In certain embodiments, gauge 104 may include ridgesand/or other features that allow a user to grip and rotate the pressuregauge for use as a handle. Allowing gauge 104 to be used as a handle foroperating assembly 100 may simplify the design of assembly 100 and/orreduce costs for manufacturing the assembly.

In certain embodiments, gauge 104 may be a dial-type pressure gauge. Adial-type pressure gauge may indicate one or more selected pressureranges (e.g., normal pressure range, low pressure range, high or overpressure range, alert pressure range, and/or danger pressure range). Thepressure ranges indicated on gauge 104 may be selected to representpressure ranges based on a desired use for assembly 100 (e.g., a type ofrefrigerant used with the assembly or a type of refrigerant systemintended for use with the assembly). In some embodiments, the indicatedpressure ranges may be color-indexed to provide additional visualindication of the pressure ranges. In some embodiments, gauge 104 may bea digital readout pressure gauge.

Gauge 104 may be coupled to pin 106. Pin 106 may be coupled to gauge 104such that a tight seal is formed between the pin and the gauge. Forexample, pin 106 may be coupled to gauge 104 using nut 107. In anembodiment, nut 107 may be a knurled press fitting. Nut 107 may becoupled (e.g., threaded, glued, epoxied, and/or welded) to pin 106 andthread onto a threaded portion of gauge 104 to form a seal (e.g., atight seal) between pin 106 and gauge 104. In some embodiments, the useof nut 107 to couple pin 106 to gauge 104 may be reversed. For example,nut 107 may be coupled to gauge 104 and thread onto a threaded portionof pin 106. In some embodiments, an o-ring or gasket inside nut 107 mayprovide a seal between pin 106, nut 107, and gauge 104.

In some embodiments, pin 106 may be permanently coupled to gauge 104.For example, pin 106 may be bonded (e.g., glued, epoxied, or welded) togauge 104. In some embodiments, pin 106 may be formed as a portion ofgauge 104. Pin 106 may be made of materials chemically inert torefrigerant (e.g., stainless steel or aluminum). Pin 106 may be coupledto gauge 104 such that the pin rotates when the gauge is turned.

Pin 106 and gauge 104 may be coupled to body 102 with nut 108. Nut 108may be a retainer nut. An inside diameter of a portion of nut 108 may beslightly larger than the outside diameter of pin 106 so that the nutmoves freely up and down the body of the pin. A portion of nut 108 mayhave an inside diameter that is less than a diameter of pin 106 atthreads 110 so that the nut does not pass over the threads. Gasket 112may be located inside nut 108 to provide a seal between pin 106, nut108, and body 102. In some embodiments, gasket 112 may include one ormore pieces that together provide a seal between pin 106, nut 108, andbody 102. Gasket 112 may be made of one or more materials that arechemically inert to fluid in assembly 100.

Pin 106 may include threads 110. Threads 110 may engage threads 114 ofbody 102 such that rotation of gauge 104 rotates pin 106. Rotation ofpin 106 may cause the pin to move along threads 110 and translaterelative to body 102. As pin 106 translates relative to body 102, thepin may form a seal when pressed against seat 115. A portion of pin 106that presses against seat 115 may be complementary to the shape of seat115 so that a tight seal is formed between the pin and the seat. Sealingpin 106 against seat 115 may inhibit flow of fluids between arefrigerant can and a hose coupled to assembly 100. Thus, assembly 100may operate as a shutoff valve between a refrigerant can and a hosecoupled to the assembly.

In certain embodiments, pin 106 may include tip 116. Tip 116 may be apiercing tip (e.g., a can piercing tip). Tip 116 may be used to pierce arefrigerant can or other refrigerant container that may be coupled toassembly 100. Tip 116 may be formed of hardened material (e.g.,stainless steel). In an embodiment, pin 106, including tip 116, is madeof one material as a single formed body. In some embodiments, pin 106may be made of two or more pieces.

Pin 106 may include hollow portion 118. Hollow portion 118 may be influid communication with gauge 104, as shown in FIG. 1. Hollow portion118 may also be in fluid communication with the interior of body 102through access port 120. Thus, gauge 104 may be used to measure apressure of fluid (e.g., refrigerant) in body 102.

Body 102 may be made of one or more materials chemically inert to fluid(e.g., refrigerant) used in a refrigerant system. In certainembodiments, body 102 may include two or more pieces of differingmaterials that are coupled (e.g., bonded). For example, body 102 mayhave a plastic outer portion coupled to or bonded over a metal (e.g.,brass) interior portion.

Body 102 may include can thread 122. Can thread 122 may be used tocouple assembly 100 to a refrigerant container (e.g., a refrigerantcan). A refrigerant container may have a threaded portion that mateswith can thread 122. Gasket 124 may be used to provide a seal betweenbody 102 and a refrigerant container. Gasket 124 may be made of one ormore materials that are chemically inert to fluid from a refrigerantcontainer. In certain embodiments, a refrigerant can may be coupled toassembly 100 with pin 106 and tip 116 in a recessed position such thatthe refrigerant can is not pierced as the can is coupled to theassembly.

In certain embodiments, can thread 122 may be selected to mateexclusively with a threaded portion of certain refrigerant containers.For example, can thread 122 may only mate with a threaded portion of anR-134a refrigerant container.

Body 102 may include hose coupler 126. Hose coupler 126 may be, forexample, a hose barb or other device for coupling a refrigerant hose toassembly 100. In certain embodiments, a hose may be permanently attachedto hose coupler 126. For example, a hose may be crimped to hose coupler126 (e.g., the hose may be crimped over the hose coupler using a metalcrimp sleeve). A hose may be coupled to hose coupler 126, however, usingany method known in the art.

FIG. 2 depicts an embodiment of a pressure gauge, valve, and hoseapparatus. Apparatus 128 may include assembly 100, hose 130, andcoupling device 132. Apparatus 128 may be used for pressure testingand/or charging of a refrigerant system (e.g., a motor vehiclerefrigerant system). In certain embodiments, apparatus 128 may be usedwith a refrigerant system that uses R-134a as the refrigerant fluid.Hose 130 may be coupled (e.g., connected with one or more interveningmembers) to assembly 100 and coupling device 132. In certainembodiments, hose 130 may be directly attached to assembly 100 and tocoupling device 132. Assembly 100 and coupling device 132 may be coupledto hose 130 with a hose coupler and crimping the hose as described aboveor by any method known in the art. Hose 130 may be a flexible hose. Hose130 may be made of materials that are chemically inert to refrigerantfluid including, but not limited to, rubber, polyvinylchloride,polyethylene, polypropylene, polytetrafluoroethylene, and mixturesthereof. Hose 130 may be 12″ or less in length. Longer lengths of hosesmay require a shutoff valve at some point along the length of the hoseto satisfy Environmental Protection Agency (EPA) regulations.

In an embodiment, coupling device 132 may be a quick coupling device(e.g., a 14 mm×13 mm quick coupler device). Coupling device 132 maycouple to an inlet port of a refrigerant system (e.g., a motor vehiclerefrigerant system). Coupling device 132 may be coupled to an inlet portof a refrigerant system by pulling back an outer connector ring as thecoupling device is pushed onto the inlet port. In certain embodiments,coupling device 132 may be designed to be coupled to only one side of arefrigerant system (e.g., a low-pressure side). Designing couplingdevice 132 to only couple to the low-pressure side of a refrigerantsystem may inhibit a user from accidentally coupling apparatus 128 to ahigh-pressure side of the refrigerant system, thus avoiding potentialsafety hazards.

In certain embodiments, apparatus 128 may be used as both a gauge formeasuring a pressure of a refrigerant system (e.g., a motor vehiclerefrigerant system) and a valve for opening and closing a refrigerantcontainer attached to the apparatus (i.e., as a shutoff valve for therefrigerant container). FIG. 3 depicts a flowchart of an embodiment of amethod for pressure testing and/or recharging a refrigerant system(e.g., a motor vehicle refrigerant system) using apparatus 128. Steps inthe method depicted in FIG. 3 may reference elements identified in theembodiments depicted in FIGS. 1 and 2. In certain embodiments, thepressure of a low-pressure side of refrigerant system may be measuredwith or without a refrigerant can coupled to apparatus 128 by usingOption 1 or Option 2, respectively, depicted in FIG. 3.

In Option 1, gauge 104 is rotated (e.g., counterclockwise) until tip 116is in a retracted position (step 134). With tip 116 in a retractedposition, accidental piercing of a refrigerant can may be avoided duringcoupling of apparatus 128 to the refrigerant can. A refrigerant can maythen be coupled to apparatus 128 using can thread 122 (step 136). A usermay start the refrigerant system (e.g., by starting the engine of amotor vehicle) and operate the refrigerant system at maximum cooling(step 138). Coupling device 132 may be coupled to a low-pressure sideservice port of the refrigerant system (step 140). (If coupling device132 is coupled to the high-pressure side service port of the refrigerantsystem, explosion of the refrigerant can may result.) After coupling tothe refrigerant system, gauge 104 may be used to measure a low-pressureside pressure of the refrigerant system (step 142). The measuredpressure may be compared to an ambient temperature pressure measurementchart (e.g., a chart supplied with apparatus 128) or adjusted (e.g.,corrected) in any other way known in the art to provide a more accuratepressure assessment based on ambient temperature of the environment.

In Option 2, gauge 104 is rotated (e.g., counterclockwise) until tip 116is extended (e.g., fully extended) (step 144). Extension of tip 116 mayinhibit refrigerant from escaping apparatus 128 during pressuremeasurement. A user may start the refrigerant system (e.g., by startingthe engine of a motor vehicle) and operate the refrigerant system atmaximum cooling (step 146). Coupling device 132 may be coupled to alow-pressure side service port of the refrigerant system (step 148).After coupling to the refrigerant system, gauge 104 may be used tomeasure a low-pressure side pressure of the refrigerant system (step150). The measured pressure may be corrected to provide more accuratepressure assessment based on ambient temperature of the environment.Apparatus 128 may be disconnected from the refrigerant system aftermeasuring the pressure and before a refrigerant can is attached to theapparatus (step 152).

If the pressure measured in step 142 or in step 150 indicates that arefrigerant level in the refrigerant system is below a desired level,apparatus 128 may be used to supply refrigerant to the refrigerantsystem. If Option 2 was used to measure the pressure, steps 134, 136,138, and 140 may be used to couple apparatus 128 to a refrigerant can.Step 142 may be skipped and the user may begin charging of therefrigerant system at step 154. If Option 1 was used to measure thepressure, a user may begin charging of the refrigerant system at step154.

In step 154, gauge 104 may be rotated (e.g., clockwise) until tip 116punctures the refrigerant can. Gauge 104 may then be rotated in anopposite direction (e.g., counterclockwise) to allow refrigerant toenter apparatus 128 (step 156). A user may hear refrigerant leaving therefrigerant can. After allowing at least some refrigerant to enter therefrigerant system, the user may rotate gauge 104 to close off the flowof refrigerant. A pressure of the refrigerant system may be assessed(step 158). If the refrigerant system pressure is still too low, steps156 and 158 may be repeated until a sufficient refrigerant systempressure is achieved. After sufficiently filling the refrigerant systemwith refrigerant, apparatus 128 may be uncoupled from the refrigerantsystem (step 160).

An empty refrigerant can may be uncoupled from apparatus 128 anddisposed of properly (e.g., recycled). Apparatus 128 may be stored withtip 116 retracted, thus inhibiting accidental piercing of a nextrefrigerant can coupled to the apparatus. If the refrigerant can is notempty, the refrigerant can may remain coupled to apparatus 128 for lateruse. Care should be taken in storing apparatus 128 and the refrigerantcan to inhibit accidental opening and/or puncturing of the refrigerantcan.

FIG. 4 depicts an embodiment of pressure measurement and chargingassembly 200. Assembly 200 may be used for assessing pressure and/orcharging of a refrigerant system (e.g., a motor vehicle refrigerantsystem). In certain embodiments, assembly 200 may be used with arefrigerant system that uses R-134a as the refrigerant fluid. Assembly200 may include outer body 202. Outer body 202 may be made of, forexample, aluminum and/or one or more other materials (e.g., plastic)that are chemically inert to refrigerant fluid. Hanger 204 may becoupled to outer body 202. Hanger 204 may be used to hang or supportassembly 200 during use (e.g., from a hood of a motor vehicle) and/orduring storage of the assembly. In some embodiments, hanger 204 may bethreaded into outer body 202. Hanger 204 may have a length, for example,of about 6″.

Assembly 200 may include low-pressure side gauge 206 and high-pressureside gauge 208. Low-pressure side gauge 206 may be used to measure alow-pressure side pressure of a refrigerant system. High-pressure sidegauge 208 may be used to measure a high-pressure side pressure of arefrigerant system. Gauge 206 and/or gauge 208 may be dial-type pressuregauges. A dial-type pressure gauge may include one or more selectedpressure ranges (e.g., normal pressure range, low pressure range, highor over pressure range, alert pressure range, and/or danger pressurerange). Pressure ranges indicated on gauges 206, 208 may be chosen torepresent pressure ranges based on a desired use for assembly 200. Forexample, low-pressure side gauge 206 may have a lower pressure range(e.g., 0 psi to about 200 psi) than high-pressure side gauge 208 (e.g.,0 psi to about 600 psi), as shown in FIG. 4. In some embodiments, theindicated pressure ranges may be color-indexed to provide additionalvisual identification of the pressure ranges. In some embodiments,gauges 206, 208 may be digital readout pressure gauges. In someembodiments, gauges 206, 208 may be located on top of outer body 202(e.g., on the same side of outer body 202 as hanger 204).

Assembly 200 may include low-pressure side coupler 210, refrigerant cancoupler 212, and high-pressure side coupler 214. FIG. 5 depicts anembodiment of a pressure measurement and charging assembly with hoses.Low-pressure side coupler 210 may be coupled to conduit 216 (e.g., ahose) that is coupled to a low-pressure side inlet port of a refrigerantsystem. Refrigerant can coupler 212 may be coupled to conduit 218 (e.g.,a hose) that is coupled to a refrigerant can. High-pressure side coupler214 may be coupled to conduit 220 (e.g., a hose) that is coupled to ahigh-pressure side inlet port of a refrigerant system. In certainembodiments, couplers 210, 212, 214 may be coupled to outer body 202.For example, couplers 210, 212, and/or 214 may be double male-NPT(National Pipe Thread) fittings with one end for coupling to outer body202 (at openings 210B, 212B, and 214B, respectively) and one end forcoupling to conduits or hoses. In this case, conduits (e.g., conduits216, 218, 220) or hoses that are coupled to the couplers may usefittings 215 that are NPT fittings (e.g., female NPT fittings). Othertypes of hose or conduit fittings known in the art may also be used. Insome embodiments, couplers 210, 212, and/or 214 may be formed as part ofouter body 202.

In some embodiments, assembly 200 may include low-pressure side storagefitting 222 and/or high-pressure side storage fitting 224 (shown inFIGS. 4 and 5). In some embodiments, low-pressure side storage fitting222 may be a double-ended fitting with one end coupled to outer body 202and one end for coupling to conduit 216. Low-pressure side storagefitting 222 may be coupled to conduit 216 using coupling device 132 tostore the conduit when the conduit is not in use. In some embodiments,high-pressure side storage fitting 224 may be a double-ended fittingwith one end coupled to outer body 202 and one end for coupling toconduit 220. High-pressure side storage fitting 224 may be coupled toconduit 220 using coupling device 226 to store the conduit when theconduit is not in use. Coupling device 226 may be a coupling device(e.g., a quick coupling device such as a 14 mm×16 mm quick couplerdevice) for coupling to a high-pressure side inlet port of a refrigerantsystem.

In certain embodiments, conduits 216, 220 may include one or more valves228. Valves 228 may be shutoff valves (e.g., ball valves). Valve 228 maybe located along a length of conduit 216 or conduit 220. In certainembodiments, valve 228 may be located 12″ or less from coupling devices132 and 226 along the length of conduit 216 or conduit 220. Valve 228may be located within this distance to comply with EPA regulations.

In some embodiments, valve 230 may be located at an end of conduit 218.Valve 230 may be a can piercing type shutoff valve. Valve 230 may beused to pierce or puncture a top of a refrigerant can. In someembodiments, valve 230 may be a can piercing type shutoff valve for useonly with 134a refrigerant cans. Valve 230 may also be used to regulateflow from the refrigerant can (i.e., valve 230 may operate as a shutoffvalve for the refrigerant can). In some embodiments, valve 230 may notoperate as a shutoff valve, but rather as an attachment that pierces arefrigerant can.

In certain embodiments, conduits 216, 218, and/or 220 may bedifferentiated by, for example, color. For example, conduit 216 may be ablue conduit, conduit 218 may be a yellow conduit, and conduit 220 maybe a red conduit. Using different colors for conduits 216, 218, 220 mayallow for easier and safer operation of assembly 200 by a user (e.g., bya non-professional user).

FIG. 6 depicts a schematic representation of a pressure measurement andcharging assembly as depicted from a front-end view of assembly 200.FIG. 6 depicts a schematic of the internal structure of an embodiment ofassembly 200. Assembly 200 may be divided into two sections,low-pressure side 300 and high-pressure side 302. On high-pressure side302, a gauge (e.g., high-pressure side gauge 208, depicted in FIGS. 4and 5) may be coupled to opening 232. Opening 232 is in fluidcommunication with opening 214B. Thus, a gauge (e.g., high-pressure sidegauge 208) may be used to measure a pressure of a high-pressure side ofa refrigerant system coupled to opening 214B.

On low-pressure side 300, as shown in FIG. 6, opening 212B is in fluidcommunication with conduit 234. Conduit 234 may be in fluidcommunication with opening 210B and opening 236. Thus, refrigerant maybe allowed to flow from a refrigerant can coupled to opening 212B to alow-pressure side of a refrigerant system coupled to opening 210B.

In an embodiment of assembly 200, fluid is not allowed to flow betweenopening 212B and opening 214B (i.e., between low-pressure side 300 andhigh-pressure side 302), which may be coupled to a high-pressure side ofa refrigerant system. This configuration inhibits a user fromaccidentally attempting to charge the refrigerant system through thehigh-pressure side of the refrigerant system. Charging through ahigh-pressure side of a refrigerant system may be dangerous and shouldbe attempted only by professional service personnel. Thus, assembly 200may be easily and safely operated by both professional service personneland non-professional consumers (e.g., motor vehicle owners).

FIGS. 7-12 depict one exemplary embodiment of assembly 200. It is to beunderstood that variations in the design, construction, and/or assemblyof assembly 200 and one or more of its components may be made withoutdeviating from the operation or function of assembly 200 as describedherein. For example, assembly 200 may be designed and assembled usingfewer pieces or parts (e.g., low-pressure side 300 and high-pressureside 302 may be a single piece cast body).

In certain embodiments, low-pressure side gauge 206 (depicted in FIGS. 4and 5) may be operated as a valve (e.g., a shutoff valve) forcontrolling a flow of refrigerant between opening 212B and opening 210Bin addition to being used to measure a pressure of a low-pressure sideof a refrigerant system. FIG. 7A depicts a cross-sectionalrepresentation of low-pressure side 300 of assembly 200 from a front-endview. As shown in FIG. 7A, low-pressure side 300 may includelow-pressure body 304. FIG. 7B depicts a cross-sectional representationof low-pressure body 304 along line C-C depicted in FIG. 7A. FIG. 7Cdepicts a cross-sectional representation of low-pressure body 304 from abottom view. FIG. 7D depicts an expanded cross-sectional representationof low-pressure body 304 along line B-B depicted in FIG. 7A.

In certain embodiments, low-pressure body 304 may be a cast body (e.g.,an aluminum die-cast body). Low-pressure body 304 may include opening236. A gauge (e.g., gauge 206 depicted in FIGS. 4 and 5) may be coupledto opening 236. In certain embodiments, a gauge may be coupled toopening 236 using a plunger (e.g., plunger 238 depicted in FIGS.11A-11D). Opening 236 may be in fluid communication with conduit 234,opening 212B, and opening 210B, as shown in FIGS. 6, 7A, and 7B.Openings 210B and/or 212B may be threaded (e.g., a ⅛″ NPT female thread)to allow for coupling to the openings.

In certain embodiments, low-pressure body 304 may include hanger opening204B. Hanger opening 204B may be used to couple to hanger 204, depictedin FIGS. 4 and 5. For example, hanger 204 may be threaded into hangeropening 204B.

In certain embodiments, low-pressure body 304 may include holes 244.Holes may include threaded portions 256A. Holes 244 and threadedportions 256A may be used to allow a pin (e.g., pin 241 depicted inFIGS. 12A and 12B) to be coupled to (e.g., located in) low-pressure body304.

FIG. 8A depicts a cross-sectional representation of high-pressure side302 of assembly 200 from a front-end view. As shown in FIG. 8A,high-pressure side 300 may include high-pressure body 305. FIG. 8Bdepicts a cross-sectional representation of high-pressure body 305 alongline A-A depicted in FIG. 8A. FIG. 8C depicts a cross-sectionalrepresentation of high-pressure body 305 from a bottom view.

In certain embodiments, high-pressure body 305 may be a cast body (e.g.,an aluminum die-cast body). High-pressure body 305 may include opening232. A gauge (e.g., gauge 208 depicted in FIGS. 4 and 5) may be coupledto opening 232. Opening 232 may be threaded (e.g., a ⅛″ NPT femalethread) to allow a gauge to be coupled to the opening. Opening 232 maybe in fluid communication with opening 214B, as shown in FIGS. 6, 8A,and 8B. Opening 214B may be threaded (e.g., a ⅛″ NPT female thread) toallow for coupling to the opening.

In an embodiment, assembly 200 may include an outer body (e.g., outerbody 202 shown in FIGS. 4 and 5) that encloses low-pressure body 304 andhigh-pressure body 305. An outer body may be formed as a single pieceincluding means for placing low-pressure body 304 and high-pressure body305 inside the outer body. In certain embodiments, an outer body mayinclude 2 or more pieces that are coupled together to form the outerbody. FIGS. 9A-10C depict an embodiment of an outer body that includestwo pieces coupled together to form the outer body. FIGS. 9A-9C depictcross-sectional representations of an embodiment of outer body frontportion 202A. FIG. 9A depicts a cross-sectional representation of anembodiment of outer body front portion 202A from a front-end view. FIG.9B depicts a cross-sectional representation of outer body front portion202A along line A-A depicted in FIG. 9A. FIG. 9C depicts across-sectional representation of outer body front portion 202A alongline B-B depicted in FIG. 9A.

As shown in FIGS. 9A-9C, outer body front portion 202A may includeopening 236B that corresponds to opening 236 of low-pressure body 304,depicted in FIGS. 7A-7D. Outer body front portion 202A may includeopening 232B that corresponds to opening 232 of high-pressure body 305,depicted in FIGS. 8A-8C. Outer body front portion 202A may include frontportions of openings 204C, 210C, 212C, 214C that correspond to openings204B, 210B, 212B, 214B, depicted in FIGS. 6-8C. In certain embodiments,outer body front portion 202A may include front portions 222A, 224A oflow-pressure side storage fitting 222 and/or high-pressure side storagefitting 224 (shown in FIGS. 4 and 5).

Outer body front portion 202A may be a molded body (e.g., an injectionmolded plastic body) or a cast body (e.g., an aluminum die cast body).As shown in FIGS. 9A-9C, outer body front portion 202A may include frontportion couplers 340A. Front portion couplers 340A may be used forcoupling outer body front portion 202A to outer body rear portion 202B,shown in FIGS. 10A-10C. In some embodiments, front portion couplers 340Amay include female threading for coupling to a screw or bolt.

FIGS. 10A-10C depict cross-sectional representations of an embodiment ofouter body rear portion 202B. FIG. 10A depicts a cross-sectionalrepresentation of an embodiment of outer body rear portion 202B from afront-end view. FIG. 10B depicts a cross-sectional representation ofouter body rear portion 202B along line A-A depicted in FIG. 10A. FIG.10C depicts a cross-sectional representation of outer body rear portion202B along line B-B depicted in FIG. 10A.

Outer body rear portion 202B may be a molded body (e.g., an injectionmolded plastic body) or a cast body (e.g., an aluminum die cast body).Outer body rear portion 202B may include rear portions of openings 204C,210C, 212C, 214C that correspond to openings 204B, 210B, 212B, 214B,depicted in FIGS. 6-8C. In certain embodiments, outer body rear portion202B may include rear portions 222B, 224B of low-pressure side storagefitting 222 and/or high-pressure side storage fitting 224 (shown inFIGS. 4 and 5).

As shown in FIGS. 10A-10C, outer body rear portion 202B may include rearportion couplers 340B. Rear portion couplers 340B may be used forcoupling outer body rear portion 202B to outer body front portion 202A,shown in FIGS. 9A-9C. In some embodiments, rear portion couplers 340Bmay be recesses that function as washers for screws or bolts to coupleouter body rear portion 202B to outer body front portion 202A.

FIGS. 11A-11D depict an embodiment of plunger 238 that may be used inopening 236, depicted in FIGS. 6-7D. FIG. 11A depicts a cross-sectionalrepresentation of an embodiment of plunger 238 from an end-on view. FIG.11B depicts a side view of an embodiment of plunger 238. FIG. 11Cdepicts a cross-sectional representation of an embodiment of plunger 238from a side view. FIG. 11D depicts an expanded cross-sectionalrepresentation of an embodiment of plunger 238 along line A-A depictedin FIG. 11A.

Plunger 238 may be placed in opening 236 (depicted in FIGS. 7A-7D) toallow a gauge (e.g., gauge 206 depicted in FIGS. 4 and 5) to be coupledto the opening. Plunger 238 may have a shape substantially similar to aninterior shape of opening 236, as shown in FIGS. 7A-7D and 11A-11D.Plunger 238 may have outer dimensions substantially similar to thedimensions of walls of opening 236 so that the plunger may fit snugly inthe opening. Plunger 238 may include sealing grooves 248A-C. Sealinggrooves 248A-C may be, for example, o-ring grooves. O-rings or anothersealing material may be placed in sealing grooves 248A-C so that a sealis made between plunger 238 and the walls of opening 236. Plunger 238may have end 245 at a forward portion of the plunger. End 245 may have ashape that appropriately matches a shape of diameter 245B of opening236, shown in FIG. 7D.

Plunger 238 may include coupling portion 250. Coupling portion 250 maybe used to couple plunger 238 to a gauge (e.g., gauge 206 depicted inFIGS. 4 and 5). In certain embodiments, coupling portion 250 may be athreaded portion so that a gauge may be coupled by threading the gaugeinto the coupling portion. For example, coupling portion 250 may be afemale threaded ⅛″ NPT fitting.

In certain embodiments, plunger 238 may include opening 239. Opening 239may allow fluids to enter interior 240 of plunger 238. Thus, a gauge(e.g., gauge 206 depicted in FIGS. 4 and 5) coupled to plunger 238 maybe used to measure a pressure of fluid (e.g., refrigerant gas orrefrigerant liquid) in interior 240 of the plunger and openings in fluidcommunication with interior 240 through opening 239. For example, agauge may measure a pressure of fluid in opening 210B when interior 240is in fluid communication with opening 210B. Thus, a gauge may be usedto indicate a pressure of fluid in opening 210B and components coupledto opening 210B (e.g., a low-pressure side of a refrigerant system).

Plunger 238 may include groove 246. Groove 246 may be used as a guidefor operation of plunger 238 within opening 236. In certain embodiments,groove 246 may have a design (e.g., a shape and length) that controlsthe movement of plunger 238. For example, groove 246 may include firstand second ends so that movement of plunger 238 is limited by the firstand second ends. Pins or other extending devices (e.g., pin 241 shown inFIGS. 12A and 12B) may be placed in holes 244, shown in FIG. 7D, forsimultaneous use as guides for groove 246. In some embodiments, one pinor one extending device may be placed in one of holes 244 as a guide forgroove 246.

FIGS. 12A and 12B depict cross-sectional representations of anembodiment of pin 241. Pin 241 may be placed in hole 244, shown in FIG.7D, to guide movement of plunger 238, shown in FIGS. 11A-11D. Pin 241may include threaded portion 256B. Threaded portion 256B may mate withthreaded portion 256A of hole 244, shown in FIG. 7D. Pin 241 may includeopening 252. Opening 252 may include, for example, a hex wrench design,a star wrench design, or other similarly designed female fitting used torotate pin 241 into hole 244 along threaded portions 256A, 256B.Extension 254 may extend into opening 236 such that the extension entersgroove 246 of plunger 238, as shown in FIGS. 13A and 13B.

FIGS. 13A and 13B depict embodiments of plunger 238 in opening 236 in anopen fluid flow position (FIG. 13A) and a closed fluid flow position(FIG. 13B). Pin 241 may be used as a guide for groove 246 so that asplunger 238 is rotated, the plunger moves back and forth along a lengthof opening 236 according to a shape of the groove. Thus, plunger 238 maybe used to open and close fluid flow between opening 234 and opening210B (i.e., plunger 238 may operate as a valve to open and close fluidflow between opening 234 and opening 210B). In certain embodiments,rotation of gauge 206 may rotate plunger 238 and cause movement of theplunger back and forth along a length of opening 236. Thus, gauge 206may be used as a handle for operating plunger 238 and opening or closingthe flow of fluid between opening 234 and opening 210B.

As shown in FIG. 13B, fluid flow may be closed off when end 245 ofplunger 238 is moved inside diameter 245B such that o-ring 242 locatedin sealing groove 248A inhibits fluid flow between opening 234 andopening 210B. As shown in FIG. 13A, fluid flow may be allowed betweenopening 234 and opening 210B when end 245 of plunger 238 is moved out ofor almost out of diameter 245B sufficiently far enough such that o-ring242 in sealing groove 248A does not inhibit flow between opening 234 andopening 210B. O-rings 242 located in sealing grooves 248B, 248C may forma seal against walls of opening 236 to inhibit fluid from exiting theopening.

In certain embodiments, assembly 200 may be used both for measuringlow-pressure side and high-pressure side pressures of a refrigerantsystem (e.g., a motor vehicle refrigerant system) and for controllablycharging the refrigerant system using a refrigerant can. FIG. 14 depictsa flowchart of an embodiment of a method for pressure testing and/orrecharging a refrigerant system (e.g., a motor vehicle refrigerantsystem) using assembly 200. The steps in the method depicted in FIG. 14may reference elements identified in the embodiments depicted in FIGS.4-13. The pressure of a low-pressure side or a high-pressure side of arefrigerant system may be measured with or without a refrigerant cancoupled to assembly 200.

In step 400, a user may turn on a refrigerant system (e.g., a motorvehicle refrigerant system) and set the refrigerant system to maximumcooling. Care should be taken by the user to ensure the compressorclutch of the refrigerant system is engaged. If the compressor clutch isnot engaged, a user may add up to about one can of refrigerant until thecompressor clutch becomes engaged. If the compressor clutch does notbecome engaged after adding refrigerant, a user may seek repair for therefrigerant system.

After turning on the refrigerant system, a user may couple assembly 200to the refrigerant system by coupling device 132 to an inlet port on alow-pressure side of the refrigerant system and coupling device 226 toan inlet port on a high-pressure side of the refrigerant system (step402). In certain embodiments, assembly 200 may be coupled to therefrigerant system with shutoff valves 228 closed (e.g., to inhibitaccidental loss of refrigerant). Coupling devices 132, 226 may be ofdifferent sizes to match the inlet port fittings for the low-pressureside and the high-pressure side of the refrigerant system, respectively.These differing sizes may inhibit a user from accidentally couplinggauges 206, 208 to the wrong inlet ports.

After coupling assembly 200 to the inlet ports of the refrigerantsystem, a user may measure pressure in the low-pressure side of therefrigerant system and/or the high-pressure side of the refrigerantsystem (step 404). Shutoff valves 228 may be opened if previouslyclosed. A user may compare these pressures to a chart or other suppliedreference to determine if refrigerant is needed and, if so, how muchrefrigerant may be needed to recharge the refrigerant system.

If additional refrigerant is needed, a user may couple a refrigerant can(e.g., an R-134a refrigerant can for an R-134a refrigerant system) toassembly 200 with valve 230 (step 406). Valve 230 may pierce therefrigerant can and, in some embodiments, may be used as a shutoff valvefor the refrigerant can.

The user may rotate gauge 206 a selected rotation in a first direction(e.g., a ¼ turn counterclockwise) to allow refrigerant to flow from therefrigerant can to the low-pressure side of the refrigerant system (step408). In certain embodiments, refrigerant may be added in smallincrements. This may inhibit overcharging of the refrigerant system. Theuser may rotate gauge 206 the selected rotation in an opposite directionto the first direction (e.g., a ¼ turn clockwise) to stop the flow ofrefrigerant to the low-pressure side of the refrigerant system (step410). In some embodiments, the user may use valve 230 to reduce or stopthe flow of refrigerant.

The user may measure the low-pressure side pressure using gauge 206after stopping the flow of refrigerant (step 412). If the pressure ofrefrigerant remains too low, steps 408-412 may be repeated until asufficient pressure (i.e., a sufficient charge of refrigerant) isachieved. After sufficiently filling the refrigerant system withrefrigerant, assembly 200 may be uncoupled from the refrigerant system(step 414). Shutoff valves 228 and/or valve 230 may be closed beforeuncoupling assembly 200 from the refrigerant system to inhibitaccidental leakage of refrigerant from the assembly and/or from therefrigerant system.

An empty refrigerant can may be uncoupled from assembly 200 and disposedof properly. Assembly 200 may be stored with shutoff valves 228 closedand valve 230 closed. This may inhibit accidental leakage of refrigerantfrom assembly 200. If the refrigerant can is not empty, the refrigerantcan may remain coupled to assembly 200 for later use. Care should betaken in storing assembly 200 and the refrigerant can so that therefrigerant can is not accidentally opened or punctured.

In this patent, certain U.S. patents, U.S. patent applications, andother materials (e.g., articles) have been incorporated by reference.The text of such U.S. patents, U.S. patent applications, and othermaterials is, however, only incorporated by reference to the extent thatno conflict exists between such text and the other statements anddrawings set forth herein. In the event of such conflict, then any suchconflicting text in such incorporated by reference U.S. patents, U.S.patent applications, and other materials is specifically notincorporated by reference in this patent.

Further modifications and alternative embodiments of various aspects ofthe invention will be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the invention. It is to beunderstood that the forms of the invention shown and described hereinare to be taken as the presently preferred embodiments. Elements andmaterials may be substituted for those illustrated and described herein,parts and processes may be reversed, and certain features of theinvention may be utilized independently, all as would be apparent to oneskilled in the art after having the benefit of this description of theinvention. Changes may be made in the elements described herein withoutdeparting from the spirit and scope of the invention as described in thefollowing claims.

1. A combination pressure measurement/refrigerant charging apparatus,comprising: a shutoff valve comprising a piercing pin and a pressuregauge, wherein the piercing pin is configured to pierce a refrigerantcan during use, and wherein the pressure gauge is configured as a handlefor operating the shutoff valve; a hose coupled to the shutoff valve ata first end of the hose; and a quick coupling device coupled to a secondend of the hose, wherein the quick coupling device is configured to becoupled to a refrigerant system.
 2. The apparatus of claim 1, whereinthe quick coupling device is configured to be coupled to a low-pressureside of the refrigerant system.
 3. The apparatus of claim 1, wherein thequick coupling device is configured to only be coupled to a low-pressureside of the refrigerant system.
 4. The apparatus of claim 1, wherein thepressure gauge is configured to indicate a pressure of the refrigerantsystem.
 5. The apparatus of claim 1, wherein the hose comprises a lengthof less than about 12″.
 6. The apparatus of claim 1, wherein the hose isflexible.
 7. The apparatus of claim 1, wherein the hose is directlyattached to the shutoff valve.
 8. The apparatus of claim 1, wherein thehose is directly attached to the quick coupling device.
 9. The apparatusof claim 1, wherein the pressure gauge is used as a handle for operatingthe shutoff valve.
 10. The apparatus of claim 1, wherein the pressuregauge is configured to be rotated to open and close the shutoff valve.11. The apparatus of claim 1, wherein the shutoff valve is configured toallow a pressure of the refrigerant system to be measured when theshutoff valve is closed.
 12. The apparatus of claim 1, wherein theshutoff valve is configured to allow fluid to flow from the refrigerantcan to the refrigerant system when the shutoff valve is open.
 13. Theapparatus of claim 1, wherein the shutoff valve comprises a seat, andwherein the shutoff valve is configured to be closed when a portion ofthe piercing pin presses against the seat.
 14. The apparatus of claim13, wherein the piercing pin is configured to be moved back and forthrelative to the seat by rotating the pressure gauge.
 15. The apparatusof claim 13, wherein the piercing pin is configured to be moved back andforth relative to the seat, thus opening and closing the shutoff valve,by rotating the pressure gauge.
 16. The apparatus of claim 1, whereinthe shutoff valve is configured to be coupled to the refrigerant can.17. The apparatus of claim 1, wherein the piercing pin comprises ahollow portion with an access port for allowing fluid from the hose toenter the hollow portion, wherein the hollow portion is in fluidcommunication with the pressure gauge, and wherein the access port isconfigured to allow fluid into the hollow portion such that the pressuregauge can indicate the pressure of the fluid.
 18. A method for pressuretesting/refrigerant charging a refrigerant system, comprising: couplinga pressure testing/refrigerant charging apparatus to a refrigerant can,wherein the apparatus comprises: a shutoff valve comprising a piercingpin and a pressure gauge, wherein the piercing pin is configured topierce the refrigerant can, and wherein the pressure gauge is a handlefor operating the shutoff valve; a hose coupled to the shutoff valve ata first end of the hose; and a quick coupling device coupled to a secondend of the hose; coupling the pressure testing/refrigerant chargingapparatus to a refrigerant system using the quick coupling device;assessing a pressure of the refrigerant system using the pressure gauge;operating the shutoff valve to open the refrigerant can if refrigerantneeds to be added to the refrigerant system; opening the shutoff valveto allow refrigerant to flow into the refrigerant system; and closingthe shutoff valve to assess the pressure of the refrigerant system afterallowing at least some refrigerant to enter the refrigerant system. 19.The method of claim 18, further comprising opening the shutoff valvebefore the pressure testing/refrigerant charging apparatus is coupled tothe refrigerant can.
 20. The method of claim 18, wherein operating theshutoff valve to open the refrigerant can comprises closing the shutoffvalve such that the piercing pin punctures the refrigerant can.
 21. Themethod of claim 18, further comprising assessing the pressure of therefrigerant system after closing the shutoff valve and opening theshutoff valve to allow more refrigerant to flow into the refrigerantsystem if the refrigerant level in the refrigerant system is below adesired level.
 22. The method of claim 18, further comprising uncouplingthe pressure testing/refrigerant charging apparatus from the refrigerantsystem after a sufficient pressure of refrigerant has been achieved inthe refrigerant system.
 23. The method of claim 22, further comprisingstoring the pressure testing/refrigerant charging apparatus with therefrigerant can coupled to the apparatus if the refrigerant can is notempty.
 24. The method of claim 18, further comprising uncoupling therefrigerant can from the pressure testing/refrigerant charging apparatusafter the refrigerant can has been emptied.
 25. The method of claim 18,further comprising using the pressure gauge as the handle to open orclose the shutoff valve.
 26. The method of claim 18, further comprisingrotating the pressure gauge to open or close the shutoff valve.
 27. Amethod for pressure testing/refrigerant charging a refrigerant system,comprising: coupling a pressure testing/refrigerant charging apparatusto a refrigerant system, wherein the apparatus comprises: a shutoffvalve comprising a piercing pin and a pressure gauge, wherein thepiercing pin is configured to pierce a refrigerant can, and wherein thepressure gauge is a handle for operating the shutoff valve; a hosecoupled to the shutoff valve at a first end of the hose; and a quickcoupling device coupled to a second end of the hose, wherein the quickcoupling device is used to couple the apparatus to the refrigerantsystem; assessing a pressure of the refrigerant system using thepressure gauge; uncoupling the pressure testing/refrigerant chargingapparatus from the refrigerant system; coupling a refrigerant can to thepressure testing/refrigerant charging apparatus if refrigerant needs tobe added to the refrigerant system; coupling the pressuretesting/refrigerant charging apparatus to the refrigerant system usingthe quick coupling device; operating the shutoff valve to open therefrigerant can; opening the shutoff valve to allow refrigerant to flowinto the refrigerant system; and closing the shutoff valve to assess thepressure of the refrigerant system after allowing at least somerefrigerant to enter the refrigerant system.
 28. The method of claim 27,further comprising closing the shutoff valve before coupling thepressure testing/refrigerant charging apparatus to the refrigerantsystem and before assessing the pressure of the refrigerant system. 29.The method of claim 27, further comprising opening the shutoff valvebefore the pressure testing/refrigerant charging apparatus is coupled tothe refrigerant can.
 30. The method of claim 27, wherein operating theshutoff valve to open the refrigerant can comprises closing the shutoffvalve such that the piercing pin punctures the refrigerant can.
 31. Themethod of claim 27, further comprising assessing the pressure of therefrigerant system after closing the shutoff valve, and opening theshutoff valve to allow more refrigerant to flow into the refrigerantsystem if the refrigerant level in the refrigerant system is below adesired level.
 32. The method of claim 27, further comprising uncouplingthe pressure testing/refrigerant charging apparatus from the refrigerantsystem after a sufficient pressure of refrigerant has been achieved inthe refrigerant system.
 33. The method of claim 27, further comprisingstoring the pressure testing/refrigerant charging apparatus with therefrigerant can coupled to the apparatus if the refrigerant can is notempty.
 34. The method of claim 27, further comprising uncoupling therefrigerant can from the pressure testing/refrigerant charging apparatusafter the refrigerant can has been emptied.
 35. The method of claim 27,further comprising using the pressure gauge as the handle to open orclose the shutoff valve.
 36. The method of claim 27, further comprisingrotating the pressure gauge to open or close the shutoff valve. 37-72.(canceled)